The present invention is related to a conveyor system and, in particular, to a conveyor system wherein a power and free conveyor having product carriers for transporting products is integrated with a monorail conveyor having utility carriers for use in conjunction with the product carriers.
Normally, after major appliances are manufactured, they are factory tested. For some appliances where testing requires only a short time period and is not complicated, such testing does not present a problem, but where the appliance must progress through an entire lengthy cycle in order to be properly tested and/or where the appliance requires special handling such as connection to a source of water or the like, such testing has often been very labor consuming and expensive. Often the appliance must be manually or machine transfered from the transport carrier to a testing carrier.
In particular, many factories have devised a linear conveyor upon which the product is placed and the product is tested as it passes down the conveyor. Normally, the product must be manually placed on and taken from the conveyor. Further, because the conveyor must be linear and the product testing may consume a substantial amount of time, the product must move either very slowly down the conveyor which limits capacity or the conveyor must be very long which is not always possible due to the dimensional constraints of the factory at which the product is produced.
Another type of prior art system utilized to test products in the past has been a rotating carousel-type device wherein the products are placed on the carousel and tested while revolving and then removed from the carousel after one full revolution. As with the previously described system, this type of system is substantially limited as to size and speed of the carousel and is quite labor intensive since it requires loading and unloading of the product relative to the carousel.
Therefore, it is desirable to have a system wherein the carrier which initially transports the product to the testing area can be utilized to likewise transport the product during the entire testing procedure and subsequently transport the product away from the testing area. Further, it is desirable for the system to allow interspacing of utility carriers among the product carriers. Such utility carriers can provide a source of water, electricity and the like to the product. Alternatively, the utility carriers can be utilized to carry testing equipment, tools for completion of the product or for testing the product and/or parts for use in conjunction with completing the product.
In the past, a monorail-type conveyor system wherein carriers have been hung from trolleys traveling on a suspended track and driven by a chain have been quite useful for certain purposes. Monorail systems are usually simple and quite well suited for closed loop applications where it is desirable for carriers to continuously move along a fixed path at a constant speed. Likewise, power and free conveyors wherein a drive chain drives a disengageable dog on a trolley supported on a track with a carrier transported by the trolley, have proved to be highly effective in certain types of transport, especially transport of product carriers of the type described above through and from manufacturing steps. The effectiveness of the power and free conveyor is especially found in that carriers can be accumulated at a particular point or can be stopped at a particular point for performing some certain function such as quick testing or the like. While a monorail conveyor is not typically designed to allow carriers conveyed thereby to stop at a particular place, such a conveyor is especially helpful in providing constant, even flow of equally spaced carriers. The present invention provides for integration of the two types of conveyors to provide for the advantages of both within the type of system described herein.